Bundling on OS X with gtkmm from Homebrew

[Kasper Peeters <kasper peeters phi-sci com>]

I have written a gtkmm app which builds fine on OS X with the gtkmm
libraries as provided by Homebrew (and with the adwaita-icon-theme
installed it even looks reasonably decent). 

I would now like to provide a .dmg bundle. However, all instructions I
could find to bundle a gtkmm app assume that I build the gtk libraries
myself with jhbuild, which I would like to avoid.

Can anyone point me to some up-to-date instructions for constructing an
app bundle based on a compilation with homebrew-provided gtk libraries?
Many thanks.

Cheers,
Kasper